Apparatus for coking liquid residuums



C. J. PRATT APPARATUS FOR COKING LIQUID RESIDUUMS Jan. 21, 1936.

Original Filed Aug. 6, 1951 3 Sheets-Sheet 1 Jan. 2l, 1936. PRATT2,028,1'66

APPARATUS FOR COKING LIQUID RESIDUUMS Original Filed Aug. '6, 1951 sSheets-Sheet 2 5 Sheets-Sheet 3 c. J. PRATT APPARATUS FOR COKING LIQUIDRESIDUUMS 1 Filed Aug. 6, 1931 Origuia Jan, 21, 1936;

Patented 1.... 21, 1936 UNITED s'ra'rrss 2,il28,166 APPARATUS FOR COKINGLIQUID BESIDUUMS at... John Pratt, St. Louis, Mo., assignor, by

mesne assignments, to J. P. Devine Manufacturlfig Co., Inc., MountVernon, 111., a c orporation of Illinois Application August 6, 1931,Serial'No. 555,401

P Renewed September 24, 1934 1 Claim. '2021 17) This inventionrelates-toan apparatus for forming coke, and with regard to certain more specificfeatures, to the method of, and apparatus for forming coke from theresiduums of an oil refinery. Among the several objects of the inventionmay.

be noted the provision of a process for continu'- ously converting heavyresiduums into coke; the

provision o'f'a process of the class described which subjects saidresiduums to a cracking and distilling operation and then to a cokingoperation; a

the provision of a process of the class described in which superheatedsteam is admitted to d y and render the product porous; the provision ofa process of theclass described which is continuous, economical, andwhich produces a high grade coke with simplified apparatus. Other ob-Jects will be. in part obvious and in part pointed out hereinafter.

' go 'Iheinvention accordingly comprisesthe elements and combinations ofelements, steps and 7 sequence of steps, features of construction andsynthesis, and arrangements of parts, which will be exemplified in thestructures and processes 35 hereinafter described, and the scope of theapplication of which will be indicated in the following claim.

In the accompanying drawings, in which are illustrated one or more ofvarious possible em- 39 bodiments of the invention,

Fig. 1 is a vertical longitudinal section, of a coking-unit embodyingthe invention;

Fig. 2 is a top plan view of the unit of Fig. 1; Fig. 3 is a verticalsection taken on line 3-3 as of dFig. 1, taken through a distillingchamber; a

Fig. 4 is a vertical section taken on linel-l of Fig. 1, taken through acoking chamber. Similar reference characters indicate corre- 4o spondingparts throughout the several views ofthe drawings.

The drawings show a unit adapted-to convert heavy hydrocarbon residuums,as for instance those obtained from an oil refinery into coke, gas

- and some relatively heavy hydrocarbon fractions.

Formerly in thus treating vresiduumsapparatus was used which carried outthe process -a batch method and the batch process had the disadvantagescommonly associated with all such types 50 of batch units, namely, poorthermal efllciency,.

loss of time, as well as the necessity of employinglarger units per unitof output. Further, with the former batch process, certain cracking vand other chemical processes deposited graph- 55 ite or'tlie like on theinteriors of the stills, thereby reducing the coemcient of heat transferof f the stills. .This resulted because the same surface that was usedfor distilling the residuums was also used for coking the residuums.

I have overcome the above difllcuities by pro- 5 viding a continuousprocess and by providing dliferent surfaces for the initial distillationand the final coking.

Referring now more particularly to Fig. 1 the apparatus for carrying outmy method, com- 10 prises a charging and distilling chamber A, and

a coking chamber B. The chamber A has a trough-shap'edsteel floor orbottom 3, which slopes downwardly to the coking chamber B. The bottompan 3 is supported by. I-beams 3. 15 Above and on the sides of the .pan3 is a wall 1 comprising a heat insulatingbrick wall 3 provided with asteel shell lining l I. Leader pipes l3 conduct vapors rising thechamber A- 'to a main header or manifold 3 which conducts 2o the vaporsto a bubble tower l'l. r

"The heavy residuumsto be coked are introduced into chamber A throughpipes'and nozzles l9 which lead 011 from a header M (Fig. 3). The

how of the liquid residuums is controlled by and drawn off through theleader pipes l3. The

stock, charged which is not thus immediately vaporized falls to thebottom 3.

A chain arrangement 23, which comprises plates or partitions 25', shapedto the contour. of the floor 3, andwhich are joined together by asuitable'chain linkage 21, is adapted to keep the residuum whichfallsti) the floor. moving toward the end of the chamber A. The linkage 21also has wheels 26 which are provided to support the .chainOn a trackil. A motor 23 continuously .drives't e chain arrangement.

. The c amber A is heated by gases from the furnaces of the cokingchamber. These gases,

by a passage 3|, enter the passage 33, comprisingthe side walls 1, abrick partition 33 and the fioor plate 3 and thereby heat the floorplate 3 to continuously crack and/or distill the. stock which fallsthereon. '.The gases leave the'passage it through; a breaching ll andenter a chimney I3.

In the chamber-B the final. coking operation is carried out. The top andside steel lined walls] continue over this chamber. The floor comprisesa moving chain grate type .of conveyor ll supported by a number ofI-beams 43. The conveyor receives the partially distilled material fromthe chamber A, and carries it through the chamber B- where it is coked.This chamber is heated by furnaces 45 which burn gas or oil and whichheat the top 41 of the furnace to an incandescence.

The grate 4| thus receives the-heat from the in'- candescent surface 41.Nozzles 49 are positioned along the chamber to superheated steam.

- A chamber C is next to the chamber B and is permit the introduction ofdivided therefrom by a partition 61 which has a tongue ll hanging down.In this chamber super heated steam is-introdueed through nozzles 5| bothabove and below the grate 4|.

A quenching chamber D is next to the chamber C and in this chamber wateris sprayed over the coke on the grate 4| from nozzles 53. A partition69; with a flap or tongue I3 separates the chambers C and D.

The chamber B, as well as chamber A, is connected by lead pipes 13 withthe main header ii.-

The chain grate II is driven by means such as a motor 55; It is to beunderstood that either the speed of the motors 29 and 55 is madevariable or' adjustable driving means is provided between the motors andtheir respective chains whereby the speed of the chains may beregulated.

- A car 51, placed outside the unit, receives the coke from the grate'llA scraper BI is provided to insure complete'removal of the coke from thegrate ll.

A walk 59 is run around the greater part of the unit and enables manualadjustment of the various valves and inspection of the operation. The

, steam lines 49 and 5| are provided with valves for from which it flowsinto the chamber A- through the nozzles IS, the flow being regulated bythevalves 20. The hot residuum oil on being sprayed into .the chamber Apartially cracks, some of the lighter fractions rising in the form ofvapor, and the remainder falling to the floor plate 3. The fractions ofthe oil falling to the floo'r plate a, partially fills the compartmentsformed by the partition plates 25,-and as the partition platesmove-forward under the action of the chain 23,

this oil is moved forward toward the end of the chamber A. Inasmuch asthe floor plated is subjected to considerable heat by means of theportion 'of the remaining fractions of the oil which fall to the floorplate is cracked and/or distilled off, so that by the time the oilreaches the end of the floor plate 3 it has become a heavy semi-solidmaterial.

As shown in Fig. l, the nozzles iii are only pro-.

vided over about half the length of the floor plate '3, thereby leavinga substantialarea for the distilling of the oil which falls to the floorplate is. The vapors which are thus distilled off from t e liquidcombined with the vapors formed at e initial cracking and vaporizationas the stock is sprayed into the chamber A from the nozzles l9, and"pass through the main header iii to the bubble tower l1.

" hot gases passing through the passage 33, a large The semi-solidmaterial which leaves the nozzies 49, the flow of the steam beingcontrolled by suitable valves 60. This steam during the cokingoperation'helps to dry the material at a lower temperature, at the sametime producing a more. porous product. Just before the product ormaterial reaches the quenching chamber D, it passes through a steamchamber in which large quantities of superheated steam isintroduced fromthe nozzles located above and below the moving grate ll. Thisintroduction of the large 20 quantities of superheated steamsubstantially removes any volatile compounds which may be left. The cokenow passes from chamber 0 into the quenching chamber D at which pointcold water from the nozzles 53 is sprayed over the coke to cool it downto a temperature in which; it will not burn when it is extracted fromthe chamber.

The cold quenching water also serves to cause separation of the cokefrom the chain grate, so that as it passes out of the. caking chamberand the quenching chamber it freely falls off from the grate. However,any coke which may stick to the grate is removed by the scraper BI.

As hereinbefore pointed out the material while passing through chamber Bis heated by means of the flat incandescent arch I! which is raised toan incandescence by means of the furnaces 45 in which gas or.oil or thelike is burned. The

hot combustion gases leaving the furnaces 43 passes through a passage 83(Fig. 2) and enters the passages 3| and .83 to heat the floor plate I.

The vapors from chamber B, which comprise steam and hydrocarbon vaporscombine with the vapors from chamber A in the main II and enter thebubble tower together. In the bubble tower the hydrocarbons arefractionated, the lighter ones being taken out at the top and passedthrough a line 65 to a jet condenser 81, and these lighter fractions areafterwards separated from the water introduced into the Jet condenser81..

The heavier fractions are either continuously or any hydrocarbon vaporsthrough the steam and water chambers C and D and at the point where thegrate ll leaves the chamber B. By thus creating a partial vacuum inchamber B a small amount of air is continuously drawn .in andpositiveprevention of any escape of gas is prevented.

It is to be understood that the temperatures of the various chambers, aswell as the rate of new of the preheated oil residuum into the cham--bar A, and of steam into the chamber B and the rate of travel of theconveyors 23 and 4| isregulated to obtain optimum operating conditions,and the values for the various' 'flows and rates is not specified in'that for different residuums and for different preheats diflerentoperating conditions would be required. It is further to be understoodthat either manual or automatic control may be provided to obtainoptimum o ating conditions.

One of the numerous advantages of my process of coking residuums is thatit is continuous, and accordingly may be continuously run incooperation, for instance, with a cracking unit, and in this way a largeamount of heat is saved because there is no substantial time lag betweenthe time that they leave the cracking still and enter'the coking plant.Furthermore, by means of continuous operation it is possible to eflfectconsiderable saving in the usual heat loss in a batch coking operation.A further advantage of the continuous operation is that a smaller unitmay be used per unit weight of output, inasmuch as the whole unit isworking at all times, and at no time is a portion of the unit inactive.

For purposes of conciseness herein the section A can be referred to asaprimary distilling section, section B a secondary distilling and cokingsection, section C as a drying section and section D as a cooling orquenching section.

In view of the above, it will be seen that the several objects of theinvention are achieved and other advantageous results attained.

As many changes could be made in carrying out the above constructions,compositions, and

processes without departing from the scope oi the invention, it isintended that all matter con-'- tained in the above description or shownin the accompanying drawings shall be interpreted as illustrative andnot in a limiting sense.

I claim:

Apparatus for coking relatively heavy liquid residuums comprising adistilling chamber havwhich the residuums tall asthey enter said cokingchamber, and which carries the residuums through the length of the saidcoking chamber, and furnaces below the residuum-receivingportion of saidgrate, said furnaces exteriorly heating both of saidchambers, butmaintaining said coking chamber at a temperature higher than that of thedistilling chamber.

CLIFTON JOHN PRA'IT.

